It has become a preferred procedure to use staples for wound closure rather than thread or filament sutures. Surgeons choose staples because of the speed with which an incision can be closed as compared with the time consuming placing and tying of thread or filament sutures. Many surgical staplers have been designed with various features. See, for example, U.S. Pat. Nos. 8,601,748, 4,014,492, 4,109,844, 4,179,057, 4,202,480, 4,258,251, 4,375, 866, 4,407,286, 4,489,875, 4,527,725, and 4,682,555. The above patents describe staplers using preformed staples without a forming anvil, staplers having a stationary forming anvil, and staplers having a movable or retractable forming anvil as well as a wide variety of feeding mechanisms to deliver each staple to the delivery point where the staple is formed during implantation into the skin and/or tissue.
Although the use of surgical staplers are wide spread, still in most cost sensitive markets, such as veterinary surgery, thread or filament sutures are still most commonly used. In an effort to decrease the cost of using surgical staplers and allow staplers to be more cost efficient, one approach is to reduce the disposable portion of the stapler into a separate cartridge assembly to be used in conjunction with a reusable handle assembly. This decoupling of the cartridge and handle assemblies in turn creates other challenges related to the retention and alignment of the cartridge inside the handle. The present invention provides a novel structure to prevent this problem as explained more fully hereinafter.